1. Field of the Invention
The present invention relates to a method of erection of constructional units and, in particular, to a method of forming a circumferentially closed concrete wall having the same cross-section over its entire height in a plurality of concrete-placing steps and in which in each subsequent step, a circumferentially closed concrete wall section is formed on an upper end of an already formed concrete wall section, and at least one circumferentially closed inner falsework is used in more than one concrete-placing steps.
“The same cross-section” means the cross-section of the wall does not change its shape and size over the entire height of the wall.
2. Description of the Prior Art
Many constructional units, such as rotundas, staircases, chimneys have circumferentially closed walls.
It is known, e.g., to use, for erection of rotundas, climbing falseworks in which two circumferentially closed falsework rings are suspended on a support frame. The space of the falsework, which is limited by the rings, is filled with concrete. After the concrete hardens, the falsework rings are released, but are lifted on the support frame so high that their lower portion still remains in the region of the outer edge of the cast wall ring. Then, the rings are again secured, the concrete is poured in, and the process is repeated until the desired height is reached. In this way, in the cylindrical edifices, one wall ring is placed on another wall ring.
Another type of a climbing falsework is shown and described in U.S. Pat. No. 1,478,653. With such climbing falseworks, the use of anchors during walling is contemplated with which the falsework elements are braced. With such anchors, an upper anchor embedded during one concrete-placing step becomes a bottom anchor during another, following concrete-placing step. In each concrete-placing step, a new anchor is embedded. The falsework is then lifted when the preceding concrete wall section is tied as the wall section with its anchors has to carry the entire weight of the falsework. The falsework itself is formed of separate panels and the panel-reinforcing frames.
Conventionally, with climbing wall formation, the process is effected in following steps. First, the inner falsework, which is to be used in the next concrete-placing step, is secured to an already formed section of the concrete wall at a predetermined height and is centered. Then, embeddable into the concrete wall, components are secured to the inner falsework at respective locations. Such components are, e.g., anchors or embeddable casings for plug sockets. In case recesses should be formed in the concrete wall, e.g., for windows or doors, corresponding falsework parts for forming the recesses or openings are secured to the falsework. Then, reinforcing means for the next formed section of the wall is mounted. Portions of the reinforcing means can be connected to the inner falsework for retaining the reinforcing means in place. Occasionally, on a mounting site, reinforcing means is secured to a bottom of a formed, circumferentially closed reinforcing means holder, is lifted with a lifting jack, and is placed, over the inner falsework secured to the wall, on a wall top. This, however, is only then possible when no opening-formed elements are attached to the inner falsework which, otherwise, would interfere with placing of the reinforcing means holder. Then, an outer falsework is attached and connected with the inner falsework for forming a circumferentially closed section of the wall, with concrete being poured into the space between the outer and inner falseworks.
An object of the invention is to provide a particularly effective and economical method of forming a circumferentially closed concrete wall.